1. Field of the Invention
This invention relates generally to scales and more particularly to a portable scale for indicating the dead weight supported by a trailer tongue.
2. Description of the Prior Art
It has been recognized that it is desirable to measure the tongue weight on trailers when loaded. Improper tongue weight can cause problems with the towing vehicle. Too little tongue weight will cause traction problems with the tow vehicle, while too much tongue weight can cause steering problems in the tow vehicle.
A method of determining trailer tongue weight often described in trailer literature utilizes a bathroom scale, a brick and a board. The board is placed so that it is supported on one end by the bathroom scale and on the other end by a brick located at approximately the same height as the bathroom scale. The trailer tongue is located midway between the bathroom scale and the supporting brick. The trailer hitch jack is then positioned on the approximate center of the board to support the trailer. The bathroom scale then indicates approximately one-half of the total tongue weight. That is, the bathroom scale reading is doubled to obtain the tongue weight. If the hitch jack is supported at a position other than the center of the board the scale reading must be multiplied by the ratio of the total board length divided by distance from the brick to the hitch jack to obtain the tongue weight. This is a recommended procedure and trailer manufacturers suggest it be carried out every time the load in the trailer is changed.
Some trailer couplings have been provided with weight indicating devices formed as a permanent part thereof. Exemplary of such trailer hitches or couplings are U.S. Pat. Nos. 3,700,053 and 3,797,594. The type of construction disclosed in these patents requires modification of the basic trailer hitch or coupling in order to accommodate the weighing device. These weighing devices can only be used to provide the tongue weight of the trailer on which they are formed. Existing trailers would require an expensive modification to have such devices formed as a part thereof.